1G Rpms go up without accelerating

[talonlan3]

This issue happened after launching at the track. I can get into every gear just fine. I can get rolling but if I give it gas the rpm’s go up and car does not accelerate. I thought it might be due to a faulty pressure plate or glazed clutch. I just replaced the clutch disk/pp/ and resurfaced flywheel to .609.
The issue is still there after replacing clutch. What else could this be?

 

[Mech Addict]

are you sure the clutch is releasing? you should be able to push in the slave cylinder shaft with the clutch pedal totally up. If you can't, then it would shift into gear fine, but wouldn't grip because the hydraulic pressure is trapped. this requires re-adjusting the clutch a little.
Otherwise, something broken in the trans?

 

[talonlan3]

I can still depress the slave cylinder towards the drivers side. I didn’t have any issues until I launched at the track. As soon as I launched the rpm’s shot through the roof and I couldn’t accelerate. No fringing happened or odd noises. I know for a fact my clutch is adjusted correctly with a new oem master,slave, pivot ball, oem clutch fork, oem release bearing, proper step height .609
When I had transmission out last week to replace the pp and clutch disk I could turn it through every gear just fine.

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[NOSLO2PT0]

Can you drive the car normally without launching? Or does the car not move at all?

 

[talonlan3]

I can get rolling but I can’t accelerate over 10mph if I had to guess. It’s so weird I’m really unsure what the issue could be besides inside transmission.
Motor idles and behaves normal.

 

[pauleyman]

Have you checked the slave since this happened? I realize you said you could push it but was this before or after the incident? If before I would check again.

 

[talonlan3]

I just got the transmission installed last night and checked it before I took it around the block. Fork sits slightly towards the drivers side in the window. There is no pressure on the fingers of the pressure plate.

 

[pauleyman]

So you dropped the trans and still didn't find the cause? Sounds like clutch to me.

 

[Mech Addict]

Ok, well unless the clutch disk is internally failed, sounds like something else at play. Any other noises? Is it awd? What would happen if, say, a part of the xfer case sheared? Then the center diff would send the power to the broken part, rev, go nowhere. Just musing aloud...

 

[talonlan3]

So you dropped the trans and still didn't find the cause? Sounds like clutch to me.

I sent flywheel out for resurface, I bought a new act 2600pp and 6 puck sprung disk (same thing I was running at the track)and installed it over the weekend. I’m 100% certain it is not clutch related.

Ok, well unless the clutch disk is internally failed, sounds like something else at play. Any other noises? Is it awd? What would happen if, say, a part of the xfer case sheared? Then the center diff would send the power to the broken part, rev, go nowhere. Just musing aloud...

Old Pressure plate had some heat spots but no failures from what I could see. Disk had seen some heat but it wasn’t really glazed.
I heard no grinds or noises at the track and even now when I drive it I hear no noises.

 

[pauleyman]

Check for a broken rear axle

 

[NOSLO2PT0]

Just tear the trans out and pull the clutch and inspect

Is it possible you have the clutch master cylinder extremely pre-loaded?

 

[talonlan3]

Just tear the trans out and pull the clutch and inspect

Already did that. Here are pictures of all the components. I already replaced these items last weekend and my problem still persists.

Is it possible you have the clutch master cylinder extremely pre-loaded?

My clutch is adjusted properly as I can still push my slave towards the drivers side of the car.

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[NOSLO2PT0]

That was a brand new disc when you installed it? I’d measure the pad thickness just for shits and grins.

Have you personally verified the step on the flywheel to be correct, or just assumed it was from the machine shop?

 

[talonlan3]

That was a brand new disc when you installed it? I’d measure the pad thickness just for shits and grins.

Have you personally verified the step on the flywheel to be correct, or just assumed it was from the machine shop?

Brand new disk and pressure plate when I installed the old one. And both new pp and disk this time as well.
Yes I verified both times when I had it resurfaced with a depth mic from my tool box at work that has been calibrated recently and his measurements match mine.
Last time I had it resurfaced it measured .608 and after the current resurface I have .609

 

[93xsg]

Hmm the only time I had something similar.
My clutch would slip at over 20 psi. But that was just too much power for the clutch.
Comparing to yours, when you reach a certain threshold the clutch slips and motor free revs?

Maybe something is binding or slipping other than clutch.

Like others said, maybe the power is going somewhere else? Like transfercase, rear axle? Center diff, rear diff? Just trying to think of every possibility.

 

[talonlan3]

I really don’t know in detail what is inside the transmission and transfer case. That’s why it’s hard for me to diagnose this issue. I figured clutch would be cheapest easiest fix so I went ahead and did it.
My assumption is leaning on a bad center diff. It’s just weird that I can get rolling from a stop but not accelerate more than 10 mph in any gear.

 

[NOSLO2PT0]

Can you feather the throttle and get above 10mph?

@pauleyman What are the signs or symptoms of a burnt up viscous coupler?

 

[92AWDHX40]

Start off with the basics and go from there, process of elimination. keep us posted.

 

[pauleyman]

Can you feather the throttle and get above 10mph?

@pauleyman What are the signs or symptoms of a burnt up viscous coupler?

If it were completely gone probably similar to this. Kinda like trying to drive with no transfer case. I'm guessing something internal broke or a broken rear axle. Axle feels like a slipping clutch too.

I still think rear axle is a good possibility.

 

[talonlan3]

Can you feather the throttle and get above 10mph?

@pauleyman What are the signs or symptoms of a burnt up viscous coupler?

I have not tried to feather the throttle to get going any faster. Just seems to “slip” almost instantly.

If it were completely gone probably similar to this. Kinda like trying to drive with no transfer case. I'm guessing something internal broke or a broken rear axle. Axle feels like a slipping clutch too.

I will check the rear axles once I’m off work in an hour

 

[Mech Addict]

Lift up all for wheels and start turning them by hand. Try in gear and in N. You might need a partner to turn two sides at a time, and see what else turns, and which way. At least try to rule out what things are not broken.

 

[NOSLO2PT0]

If it were completely gone probably similar to this. Kinda like trying to drive with no transfer case. I'm guessing something internal broke or a broken rear axle. Axle feels like a slipping clutch too.

I broke a rear axle at the shoot out years ago. Definitely didn’t feel like a slipping clutch to me. It sheared off in the diff, so I just unbolted the axle from the hub and drove home on three axles

 

[pauleyman]

I broke a rear axle at the shoot out years ago. Definitely didn’t feel like a slipping clutch to me. It sheared off in the diff, so I just unbolted the axle from the hub and drove home on three axles

Might depend on if the car is lsd or not. Was yours?

 

[talonlan3]

Mine has LSD diff.
I stopped by and looked at the axles. All looks good besides a newly discovered leak. Seems to be a clue something is wrong here because it never leaked from here before. I will drain it and pop the cover off tomorrow afternoon.

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